JPH0241818B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic disk device, and particularly to a servo head and a data head (hereinafter, the servo head and the data head are collectively referred to as a magnetic head) even when performing high-density recording. This invention relates to a magnetic disk device that can prevent off-track.

[Background of the Invention] In a movable head type magnetic disk device, a magnetic head is positioned at a desired track on a magnetic disk surface by servo control. In this case, as soon as there is a request to retrieve specific information on the magnetic disk surface, the magnetic head must move rapidly in the radial direction of the magnetic disk in order to shorten the retrieval time. Therefore, a relatively high-output voice coil motor is used to drive the magnetic head for moving and positioning the head.

However, when the high-output voice coil motor fixed to the base performs rapid operation due to a call command, etc., the carriage that supports the magnetic head vibrates due to the impact caused by the rapid acceleration/deceleration control, and the vibration causes A bending moment is also generated with respect to the base of the magnetic disk device, causing off-track of the magnetic disk device.

Such problems are becoming increasingly serious as recording density increases. A conventional magnetic head positioning mechanism that addresses this problem will be explained with reference to the drawings.

FIG. 1 is a perspective view of a conventional magnetic head positioning mechanism, and FIG. 2 is a partially sectional view thereof.

This positioning mechanism has a carriage 13, shown by an arrow A, centered around a pivot shaft 6, which is equipped with a servo head arm 5 that holds a servo head 2, and a data head arm 4 that holds a plurality of data heads 3 that write/read information. It is fixed to an I-shaped carriage block 9 via a needle-type bearing 12 so as to be rotatable as shown in FIG.
The magnet 7 of the voice coil motor is fixed to the side surface of the carriage block 9 with a screw 11, and the voice coil 8 of the voice coil motor is fixed to the side surface of the carriage block 9 with a screw 11.
is connected to the carriage 13. The voice coil motor connects its voice coil 8 to the carriage 1.
3 and the carriage 13 is rotatably supported by the pivot shaft 6 to form a rotary actuator. By controlling this voice coil motor with a servo signal obtained from the servo head 2, the data head 3 is positioned at a desired track on the magnetic disk 1.

In this positioning mechanism, the magnet 7
, two magnetic supports 15 and bolts 14
and fixed on the base 17 with the screw 16 through the mounting hole 10 provided in the magnetic support 15 to improve the rigidity against the rotational moment (in the direction of the arrow A) during acceleration and deceleration of the rotary actuator. At the same time, the vibration is decelerated by the damping mass 18 placed on the carriage block 9, and the carriage 13 relative to the base 17 is
The bending moment (direction of arrow B in Figure 2) is reduced.

However, the above positioning mechanism does not include parts for holding the magnet 7 (magnet support 15,
bolts 14, screws 16, etc.), damping mass 18
This method requires a large number of parts, which not only increases the number of assembly steps, but also increases the weight and size of the device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the drawbacks of the prior art as described above and to realize a vibration absorption mechanism with a small and lightweight structure for absorbing vibrations generated during acceleration and deceleration of a rotary actuator.

[Summary of the invention]

To achieve the above object, the present invention includes a carriage that supports a magnetic head via a head arm, a support portion that rotatably supports the carriage, and a device that positions the magnetic head at a desired position by rotationally driving the carriage. In a magnetic disk device including a rotary actuator comprising a drive unit, the support unit includes a rotating shaft to which the carriage is fixed, and a bearing rotatably supporting the rotating shaft, and the supporting unit includes a plurality of rotary actuators on the rotating shaft. The present invention is characterized in that a notch is provided, a track direction preloading top and a spring are inserted into the notch, and the notch is filled with a vibration absorbing material.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 3 is a perspective view of a magnetic head positioning mechanism of a magnetic disk device showing one embodiment of the present invention, and FIG. 4 is a sectional view of the pivot portion thereof.

The carriage 13 is equipped with a servo head arm 5 that holds a servo head 2, and a data head arm 4 that holds a data head 3 that writes/reads information, and a voice coil 8 of a voice coil motor is formed at one end of the servo head arm 5. It is fastened to the pivot shaft 6 by a screw 27.

The pivot shaft 6 passes through the carriage 13 in the vertical direction and is rotatably supported by a pair of upper and lower needle bearings 12 which are fixed to the carriage block 9 by means such as press-fitting or gluing.

The carriage block 9 is attached to a base (not shown) through a mounting hole 10 with a screw (not shown). A magnet 7 is fixed to the side surface of the carriage block 9, and this magnet 7 is combined with a voice coil 8 formed on the carriage 13 to constitute a voice coil motor.

The center of rotation of the pivot shaft 6 is supported by the two upper and lower needle type bearings 12, and the thrust direction is supported by one thrust bearing 2.
It is supported by 3. The pivot shaft 6 also has the two upper and lower needle type bearings 1.
A notch is provided at a position opposite to the track direction preloading top 20 and a preloading spring 21, respectively, in these two notches.
is arranged to create pressure between the pivot shaft 6 and the needle type bearing 12, and to create pressure between the outer diameter of the pivot shaft 6 and the needle type bearing 12.
'Backlash' in the track direction caused by the difference between the inner diameter of
In addition to preventing vibrations, it also absorbs vibrations in the track direction.

Furthermore, a preloading piece 2 is provided in the notch.
A vibration absorbing material 19 (for example, grease) with an appropriate viscosity is filled so as to surround the preload spring 21 and the preload spring 21, and synergistically with the vibration absorbing effect of the preload top 20 and the preload spring 21, the pivot shaft 6 and the needle type bearing are The vibration damping characteristics between 12 and 12 have been significantly improved. Moreover, when a fluid material such as grease is used as the vibration absorbing material 19, the direction of vibration to be absorbed is not limited to one direction, but vibrations in all directions can be absorbed.

Further, the thrust bearing 23 is fixed to the carriage block 9 by a screw 22, and a thrust preload is applied by a preload spring 24, a washer 26, and a screw 25 to prevent vertical movement of the pivot shaft 6 due to impact or the like. . It goes without saying that the vertical vibration of the pivot shaft 6 that cannot be absorbed completely by the preload spring 24 is absorbed by the vibration absorbing material 19 filled in the notch.

This embodiment does not require a large, large-mass magnetic support or damping mass that was required in the prior art, and can absorb vibrations during acceleration and deceleration of the rotary actuator with a small and lightweight structure.

Note that in the above description, grease was used as an example of the vibration absorbing material 19, but other materials such as magnetic fluid may also be used. However, when a magnetic fluid is used as the vibration absorbing material 19, it is necessary to configure the structure so that magnetic flux is generated in the notch.

In this way, a notch is provided in the pivot shaft 6, the preloading piece 20 and the preloading spring 21 are placed in the notch, and the vibration absorbing material 19 is filled so as to wrap the preloading piece 20 and the preloading spring 21. The aim is to improve the vibration damping characteristics. Therefore, when the voice coil motor is controlled by the servo signal obtained from the servo head 2 to position the data head 3 on a predetermined track on the magnetic disk 1, vibrations are generated due to rapid acceleration and deceleration of the voice coil motor. However, since the vibration of the pivot shaft 6 does not increase (the resonance peak is low), it is possible to prevent off-track of the magnetic head.

〔Effect of the invention〕

As explained above, according to the present invention, a notch is provided in the pivot shaft of a rotary actuator, a track direction preloading piece and a preloading spring are provided in the notch, and the gap between these is filled with a vibration absorbing material. As a result, a vibration absorption mechanism for absorbing vibrations generated during acceleration and deceleration of the rotary actuator can be realized with a small and lightweight structure.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional head positioning mechanism, FIG. 2 is a partial sectional view of FIG. 1, FIG. 3 is a perspective view showing a head positioning mechanism according to an embodiment of the present invention, and FIG. FIG. 4 is a partial cross-sectional view of FIG. 3; 6: Pivot shaft, 8: Voice coil,
9: Carriage block, 12: Needle type bearing, 13: Carriage, 19: Vibration absorber,
20: Preload top, 21, 24: Preload spring, 22, 25, 27: Screw, 23: Thrust bearing, 26: Washer.

Claims (1)

[Claims] 1. A rotary actuator consisting of a carriage that supports a magnetic head via a head arm, a support section that rotatably supports the carriage, and a drive section that positions and drives the magnetic head at a desired position by rotationally driving the carriage. In the magnetic disk device, the supporting portion includes a rotating shaft to which the carriage is fixed, and a bearing that rotatably supports the rotating shaft, and the rotating shaft is provided with a plurality of notches, and the rotating shaft is provided with a plurality of notches, and A magnetic disk device characterized in that a top for preloading in a track direction and a spring are inserted, and the notch is filled with a vibration absorbing material.